Electroless deposition process on a silicon contact

Abstract

Embodiments as described herein provide methods for depositing a material on a substrate during electroless deposition processes, as well as compositions of the electroless deposition solutions. In one embodiment, the substrate contains a contact aperture having an exposed silicon contact surface. In another embodiment, the substrate contains a contact aperture having an exposed silicide contact surface. The apertures are filled with a metal contact material by exposing the substrate to an electroless deposition process. The metal contact material may contain a cobalt material, a nickel material, or alloys thereof. Prior to filling the apertures, the substrate may be exposed to a variety of pretreatment processes, such as preclean processes and activations processes. A preclean process may remove organic residues, native oxides, and other contaminants during a wet clean process or a plasma etch process. Embodiments of the process also provide the deposition of additional layers, such as a capping layer.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims benefit of U.S. Ser. No. 60 / 663,493, filed Mar. 18, 2005 (9916L), U.S. Ser. No. 60 / 683,599, filed May 23, 2005 (9916L.02), U.S. Ser. No. 60 / 703,538, filed Jul. 29, 2005 (9916L.03), U.S. Ser. No. 60 / 703,633, filed Jul. 29, 2005 (9916L.04), U.S. Ser. No. 60 / 709,564, filed Aug. 19, 2005 (9916L.05), U.S. Ser. No. 60 / 754,230, filed Dec. 27, 2005 (9916L.06), and U.S. Ser. No. 60 / 731,624, filed Oct. 28, 2005 (10659L), which are all herein incorporated by reference in their entirety.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] Embodiments of the invention generally relate to methods for depositing materials on substrates, and more specifically to methods for filling apertures within a high aspect ratio contact. [0004] 2. Description of the Related Art [0005] Multilevel, 45 nm node metallization is one of the key technologies for the next generation of very large scale integration (VLSI). The multil...

AI Technical Summary

Benefits of technology

The patent describes methods for depositing materials on a substrate using electroless deposition processes. The methods involve exposing the substrate to a preclean process to remove contaminants, such as native oxides or other substances, and then exposing it to a first electroless solution containing a cobalt source and a second electroless solution containing a nickel source. The substrate may also be exposed to a plasma or an activation solution prior to the deposition process. The methods can be used to deposit various metal-containing layers, such as nickel, nickel phosphide, nickel boride, cobalt, cobalt tungsten, cobalt tungsten phosphide, cobalt tungsten boride, cobalt nickel, cobalt phosphide, cobalt nickel phosphide, and others. The methods can be used to fill apertures in a substrate with metal materials, such as cobalt or cobalt-nickel alloys. The substrate can also be rinsed with a variety of solutions after each exposure. The methods provide a simple and effective way to deposit materials on a substrate using electroless deposition processes.

Problems solved by technology

Although copper and tungsten are popular interconnect materials, deposition processes for depositing these materials may suffer by forming a void or a seam within the contact plug, as illustrated in FIG. 1C.

Defects, such as a seam or void 114, may cause a series of problems during the fabrication of electronic devices depicted herein.

However, a more serious obstacle during fabrication is the displacement of voids from one layer to the next.

Ultimately, the defects in conductive layer 112 can affect the device yield of the fabricated substrate.

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